Berger A, Alcaraz de la Osa R, Suszka A K, Pancaldi M, Saiz J M, Moreno F, Oepen H P, Vavassori P
CIC nanoGUNE, E-20018 Donostia-San Sebastian, Spain.
Grupo de Óptica. Departamento de Física Aplicada. Universidad de Cantabria, Avenida de los Castros s/n, Santander, Spain.
Phys Rev Lett. 2015 Oct 30;115(18):187403. doi: 10.1103/PhysRevLett.115.187403.
We report unexpected enhancements of the magneto-optical effect in ferromagnetic Permalloy disks of diameter D<400 nm. The effect becomes increasingly pronounced for smaller D, reaching more than a 100% enhancement for D=100 nm samples. By means of experiments and simulations, the origin of this effect is identified as a nanoscale ring-shaped region at the disk edges, in which the magneto-optically induced electric polarization is enhanced. This leads to a modification of the electromagnetic near fields and causes the enhanced magneto-optical excitation, independent from any optical resonance.
我们报道了直径D<400nm的铁磁坡莫合金盘中磁光效应的意外增强。对于较小的D，这种效应变得越来越明显，对于D = 100nm的样品，增强超过100%。通过实验和模拟，确定这种效应的起源是盘边缘的纳米级环形区域，其中磁光诱导的电极化增强。这导致了电磁近场的改变，并引起了增强的磁光激发，与任何光学共振无关。
